Childbirth is one of the most painful events that a woman is likely to experience, and thus is a major concern for most parturient. Severe pain releases stress mediators and may thus compromise fetus well-being if placental perfusion is decreased. Epidural analgesia is the golden standard for the management of severe labor pain. However, it could not always be used both due the parturient related factors and the organizational reasons.However, the knowledge on safety and efficacy of oxycodone involving mother, fetus and newborn is limited.